public class CategoriesAdapter extends RecyclerView.Adapter<CategoriesAdapter.ViewHolder> {

    private List<Category> categories;
    private Context ctx;

    public CategoriesAdapter(List<Category> categories, Context ctx) {
        this.categories = categories;
        this.ctx = ctx;
    }

    @Override
    public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
        View v = LayoutInflater.from(parent.getContext())
                .inflate(R.layout.list_categories, parent, false);
        return new ViewHolder(v);
    }

    @Override
    public void onBindViewHolder(CategoriesAdapter.ViewHolder holder, int position) {
        final Category category = categories.get(position);
        holder.textViewCategoryName.setText(category.getName());
    }

    @Override
    public int getItemCount() {
        return categories.size();
    }




    public class ViewHolder extends RecyclerView.ViewHolder{

        public TextView textViewCategoryName;

        public ViewHolder(final View itemView) {
            super(itemView);

            textViewCategoryName = (TextView) itemView.findViewById(R.id.textViewCategoryName);
            itemView.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {
                    Fragment fragment = null;
                    Category category =(Category) categories.get(getAdapterPosition());

                    switch (category.getName()){
                        case "Смартфон":
                            fragment = new SearchSmartphoneFragment();
                            break;
                        case "Планшет":
                            break;
                    }
                    if (fragment != null) {
                        FragmentManager fragmentManager = getFragmentManager();
                        FragmentTransaction ft = fragmentManager.beginTransaction();
                        ft.replace(R.id.content_frame,fragment);
                        ft.commit();
                    }


                }
            });

        }
    }
}

FragmentManager fragmentManager = ((Activity) itemView.getContext()).getFragmentManager();

interface ClickToProfile {
        fun openProfile(user: User)
}


class PeopleAdapter(context: Context, private var items: MutableList<User>, private var clickToProfile: ClickToProfile) :
            RecyclerView.Adapter<PeopleViewHolderItem>() {

        private val inflater: LayoutInflater = LayoutInflater.from(context)

        override fun onBindViewHolder(viewHolder: PeopleViewHolderItem, position: Int) {
            viewHolder.bindTo(items[position])
        }

        override fun onCreateViewHolder(viewGroup: ViewGroup, viewType: Int): PeopleViewHolderItem {
            return PeopleViewHolderItem.create(inflater, viewGroup, clickToProfile)
        }

        override fun getItemCount(): Int {
            return items.size
        }
    }

private fun setupRecyclerView(users: ArrayList<User>) {
    adapter = PeopleAdapter(context!!, users, object : ClickToProfile {
        override fun openProfile(user: User) {
            adapter.notifyDataSetChanged()
            listener?.replaceFragment(ProfileFragment.newInstance(user), true)
        }
    })
    recyclerView.adapter = adapter
}

class PeopleViewHolderItem private constructor(view: View,
                                               private val clickToProfile: ClickToProfile) : RecyclerView.ViewHolder(view) {
    private val itemHuman = view.itemPeople
    @SuppressLint("SetTextI18n")
    fun bindTo(user: User) {
        // listener
        itemHuman.setOnClickListener { selectAndOpen(user) }
        itemHuman.moreBtn.setOnClickListener { selectAndOpen(user) }
    }

    private fun selectAndOpen(user: User) {
        clickToProfile.openProfile(user)
        selectedPosition = layoutPosition
    }

    companion object {
        var selectedPosition = -1
        fun create(inflater: LayoutInflater,
                   parent: ViewGroup, clickToProfile: ClickToProfile): PeopleViewHolderItem {
            return PeopleViewHolderItem(inflater.inflate(R.layout.item_people, parent, false), clickToProfile)
        }
    }
}